Purge solution

ABSTRACT

A composition comprising a polypropylene glycol, a polyethylene glycol ester, an amine, and optionally an alcohol. The composition can be used as a purge solution to clean paint equipment.

BACKGROUND OF THE INVENTION

Paint equipment from time to time will need to be cleaned. The equipmentwill need cleaned when there is a build up coating material on the paintequipment or when switching between coating materials.

Purge solutions can be used to clean paint equipment. When using purgesolutions, it is desired to minimize the volatile organic content (VOC)of the purge solution to minimize the amount of organic emissions.

One type of paint equipment is a high-speed rotary atomizer. Paint issupplied through a bell cup. As the paint supply is triggered on andoff, paint can dry on the bell. A purge cycle is used to clean the bellby supplying alternating amounts of purge solution and air through theatomizer. Materials that are hard to clean require purge solutions withhigher concentration of solvents or large volumes of purge solution toclean the material. This can result in increased VOC emissions.

SUMMARY OF THE INVENTION

A composition comprising a polypropylene glycol, a polyethylene glycolester, an amine, and optionally an alcohol.

DETAILED DESCRIPTION

As used throughout, ranges are used as a shorthand for describing eachand every value that is within the range. Any value within the range canbe selected as the terminus of the range. “A” and “an” as used hereinindicate “at least one” of the item is present; a plurality of suchitems may be present, when possible. “About” when applied to valuesindicates that the calculation or the measurement allows some slightimprecision in the value (with some approach to exactness in the value;approximately or reasonably close to the value; nearly). If, for somereason, the imprecision provided by “about” is not otherwise understoodin the art with this ordinary meaning, then “about” as used hereinindicates a possible variation of up to 5% in the value.

The present invention relates to a composition that can be used as apurge solution. The composition includes a polypropylene glycol, apolyethylene glycol ester, an amine, and optionally an alcohol.Preferably, the alcohol is present in the composition.

In a preferred embodiment, the composition has VOC content of 2 lb/galor less. Preferably, it has a VOC content of 1 lb/gal or less.

The composition includes, based on weight, from about 40 to about 80weight % polypropylene glycol, from about 20 to about 60 weight %polyethylene glycol ester, from about 1 to about 10 weight % amine, andfrom 0 to about 30 weight % alcohol. The composition may alternativelyinclude, based on weight, from about 45 to about 65 weight %prolypropylene glycol, from about 18 to about 32 weight % polyethyleneglycol ester, from about 2 to about 8 weight % amine and from about 10%to about 30 weight % alcohol.

The polypropylene glycol can be any polypropylene glycol. Preferably,the polypropylene glycol has a number average molecular weight of fromabout 600 to about 1200. A preferred polypropylene glycol is availablefrom BASF Corporation as PLURACOL® P1010 (CAS No. 25322-69-4), which hasa number average molecular weight of about 1000.

The polyethylene glycol ester is a mono or diester of a fatty acid oroil reacted with a polyethylene glycol. Preferably, the polyethylene:glycol ester has a number average, molecular weight from about 200 to1450. A preferred polyethylene glycol ester is available from BASFCorporation as MAPEG® 400 MOT (CAS No. 61791-00-2), which has a numberaverage molecular weight of about 400.

The amine can be any amine. Examples of the amine include, but are notlimited to, dimethylethanol amine, ethanolamine, propanolamine,3-amino-1-propanol, methylethanolamine 2-amino-2methyl-1-propanol, and2-amino-1-butanol. Preferably, the amine is dimethylethanol amine(DMEA).

Optionally, an alcohol can be included in the composition. The alcoholcan be any alcohol. Preferably, the alcohol is an aliphatic monohydricalcohol. Preferably, the aliphatic monohydric alcohol is water solubleand contains 1 to 5 carbon atoms. A preferred alcohol is n-butanol. In apreferred embodiment, the amount of the alcohol can be up to 40% byweight of the composition. It is preferred to minimize the amount ofalcohol in order to minimize VOC. In a preferred embodiment, the alcoholis present at 20% by weight of the composition. In another embodiment,no alcohol is present in the composition.

The composition can be used as a purge solution. The composition asprovided is generally diluted to a desired concentration with a solvent.The solvent can be any solvent that can solubilize the composition.Preferably, the solvent does not contribute to VOC. In a preferredembodiment, the solvent is water. Preferably, the composition is dilutedto 10 to 30 weight % based on the weight of the composition in thesolvent.

The diluted composition is applied to paint equipment to clean theequipment.

The composition can be supplied as a concentrate, and it can be dilutedat the paint equipment site. The composition produces little or no foamwhen the composition is circulated through equipment. Also, whenagitated, the composition forms a stable dispersion.

SPECIFIC EMBODIMENTS OF THE INVENTION

The invention is further described in the following examples. Theexamples are merely illustrative and do not in any way limit the scopeof the invention as described and claimed.

EXAMPLE 1

The following composition was prepared. Weight % in Material Trade NameCAS # composition polypropylene PLURACOL ® P1010 25322-69-4 61% glycolfrom BASF polyethylene MAYPEG ® 400 MOT 61791-00-2 34% glycol ester fromBASF dimethylethanol 108-01-0  5% amineThe composition has a VOC content of 0.67 lb./gal.

The composition was diluted to a 10% by weight solution and a 20% byweight solution of the composition in water.

Test panels were prepared by applying a non-ionic polyurethanedispersion (available from BASF as E 54 waterborne basecoat) to a 4″×6″glass plate to form a 4 mil wet film using a 3″ drawdown bar. The platewas flashed for 30 minutes at 120° F. The film was placed at a 15°angle. Using a pipet, 60 drops of dilute solution were dripped onto thefilm for one minute. The area of contact wars then rated for dissolvingand/or lifting. Additionally, a control was prepared using PARCASOL® 277solution from Henkel. Both the 10% and 20% solutions showed moredissolving and/or lifting than the control.

EXAMPLE 2

The following composition was prepared. Weight % in Material Trade NameCAS # composition polypropylene PLURACOL ® P1010 25322-69-4 51.2 glycolfrom BASF polyethylene MAYPEG ® 400 MOT 61791-00-2 24.8 glycol esterfrom BASF dimethylethanol 108-01-0 4 amine n-butanol 71-36-3 20The composition has a VOC content of 2 lb./gal.

The composition was diluted to a 15% by weight solution of thecomposition in water.

Test panels were prepared as in Example 1. The solution showed moredissolving and/or lifting than the control.

It should be appreciated that the present invention is not limited tothe specific embodiments described above, but includes variations,modifications and equivalent embodiments defined by the followingclaims.

1. A composition comprising a polypropylene glycol, a polyethyleneglycol ester, an amine, and optionally an alcohol.
 2. The composition ofclaim 1, wherein the alcohol is present.
 3. The composition of claim 1,wherein the composition comprises, by weight, from about 40 to about 80weight % polypropylene glycol, from about 20 to about 60 weight %polyethylene glycol ester, from about 1 to about 10 weight % amine, andfrom 0 to about 30 weight % alcohol.
 4. The composition of claim 1,wherein the composition comprises, by weight, from about 45 to about 65weight % polypropylene glycol, from about 18 to about 32 weight %polyethylene glycol ester, from about 1 to about 10 weight % amine, andfrom about 10 to about 30 weight % alcohol.
 5. The composition of claim1, wherein the polypropylene glycol has a number average molecularweight of from about 600 to about
 1200. 6. The composition of claim 1,wherein the polyethylene glycol ester has a number average molecularweight from about 200 to
 1450. 7. The composition of claim 1, whereinthe amine is selected from the group consisting of dimethylethanolamine, see above, and combinations thereof.
 8. The composition of claim1, wherein the amine is dimethylethanol amine.
 9. The composition ofclaim 1, wherein the alcohol is an aliphatic monohydric alcohol.
 10. Thecomposition of claim 1, wherein the alcohol is an aliphatic monohydricalcohol having 1 to 5 carbon atoms.
 11. The composition of claim 1,wherein the alcohol is n-butanol.
 12. The composition of claim 1,wherein the composition comprises the polypropylene glycol, thepolyethylene glycol ester, dimethylethanol amine, and n-butanol.
 13. Thecomposition of claim 1, wherein the composition comprises 61% by weightof the polypropylene glycol, 34% by weight of the polyethylene glycolester, and 5% by weight of dimethylethanol amine.
 14. The composition ofclaim 1, wherein the composition comprises 51.2% by weight of thepolypropylene glycol, 24.8% by weight of the polyethylene glycol ester,4% by weight of dimethylethanol amine, and 20% by weight of n-butanol.15. The composition of claim 1 further comprising a solvent.
 16. Thecomposition of claim 15, wherein the composition is present in acombined amount of the composition and solvent in an amount from about10 to about 30% by weight.
 17. The composition of claim 1 furthercomprising water.
 18. The composition of claim 17, wherein thecomposition is present in a combined amount of the composition and waterin an amount from about 10 to about 30% by weight.
 19. A methodcomprising applying the composition of claim 1 to paint equipment.
 20. Amethod comprising applying the composition of claim 15 to paintequipment.
 21. A method comprising applying the composition of claim 17to paint equipment.